Add keyreader API

src/main/java/org/pgpainless/pgpainless/PGPainless.java

@@ -15,17 +15,14 @@
  */
 package org.pgpainless.pgpainless;
 
-import java.io.ByteArrayInputStream;
 import java.io.IOException;
 
-import org.bouncycastle.bcpg.ArmoredInputStream;
 import org.bouncycastle.openpgp.PGPException;
-import org.bouncycastle.openpgp.PGPPublicKeyRing;
-import org.bouncycastle.openpgp.operator.bc.BcKeyFingerprintCalculator;
 import org.pgpainless.pgpainless.algorithm.CompressionAlgorithm;
 import org.pgpainless.pgpainless.algorithm.SymmetricKeyAlgorithm;
 import org.pgpainless.pgpainless.decryption_verification.DecryptionBuilder;
 import org.pgpainless.pgpainless.encryption_signing.EncryptionBuilder;
+import org.pgpainless.pgpainless.key.KeyRingReader;
 import org.pgpainless.pgpainless.key.generation.KeyRingBuilder;
 import org.pgpainless.pgpainless.symmetric_encryption.SymmetricEncryptorDecryptor;
 
@@ -43,8 +40,13 @@ public class PGPainless {
         return new DecryptionBuilder();
     }
 
-    public static PGPPublicKeyRing publicKeyRingFromBytes(byte[] bytes) throws IOException {
+    /**
-        return new PGPPublicKeyRing(new ArmoredInputStream(new ByteArrayInputStream(bytes)), new BcKeyFingerprintCalculator());
+     * Read some existing OpenPGP key ring.
+     *
+     * @return KeyRingReader which offers reading operations
+     */
+    public static KeyRingReader readKeyRing() {
+        return new KeyRingReader();
     }
 
     /**

src/main/java/org/pgpainless/pgpainless/key/KeyRingReader.java

@@ -0,0 +1,99 @@
+package org.pgpainless.pgpainless.key;
+
+import java.io.ByteArrayInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.nio.charset.Charset;
+
+import org.bouncycastle.openpgp.PGPException;
+import org.bouncycastle.openpgp.PGPPublicKeyRing;
+import org.bouncycastle.openpgp.PGPPublicKeyRingCollection;
+import org.bouncycastle.openpgp.PGPSecretKeyRing;
+import org.bouncycastle.openpgp.PGPSecretKeyRingCollection;
+import org.bouncycastle.openpgp.PGPUtil;
+import org.bouncycastle.openpgp.operator.bc.BcKeyFingerprintCalculator;
+
+public class KeyRingReader {
+
+    public static final Charset UTF8 = Charset.forName("UTF-8");
+
+    public PGPPublicKeyRing publicKeyRing(InputStream inputStream) throws IOException {
+        return readPublicKeyRing(inputStream);
+    }
+
+    public PGPPublicKeyRing publicKeyRing(byte[] bytes) throws IOException {
+        return publicKeyRing(new ByteArrayInputStream(bytes));
+    }
+
+    public PGPPublicKeyRing publicKeyRing(String asciiArmored) throws IOException {
+        return publicKeyRing(asciiArmored.getBytes(UTF8));
+    }
+
+    public PGPPublicKeyRingCollection publicKeyRingCollection(InputStream inputStream)
+            throws IOException, PGPException {
+        return readPublicKeyRingCollection(inputStream);
+    }
+
+    public PGPPublicKeyRingCollection publicKeyRingCollection(byte[] bytes) throws IOException, PGPException {
+        return publicKeyRingCollection(new ByteArrayInputStream(bytes));
+    }
+
+    public PGPPublicKeyRingCollection publicKeyRingCollection(String asciiArmored) throws IOException, PGPException {
+        return publicKeyRingCollection(asciiArmored.getBytes(UTF8));
+    }
+
+    public PGPSecretKeyRing secretKeyRing(InputStream inputStream) throws IOException, PGPException {
+        return readSecretKeyRing(inputStream);
+    }
+
+    public PGPSecretKeyRing secretKeyRing(byte[] bytes) throws IOException, PGPException {
+        return secretKeyRing(new ByteArrayInputStream(bytes));
+    }
+
+    public PGPSecretKeyRing secretKeyRing(String asciiArmored) throws IOException, PGPException {
+        return secretKeyRing(asciiArmored.getBytes(UTF8));
+    }
+
+    public PGPSecretKeyRingCollection secretKeyRingCollection(InputStream inputStream)
+            throws IOException, PGPException {
+        return readSecretKeyRingCollection(inputStream);
+    }
+
+    public PGPSecretKeyRingCollection secretKeyRingCollection(byte[] bytes) throws IOException, PGPException {
+        return secretKeyRingCollection(new ByteArrayInputStream(bytes));
+    }
+
+    public PGPSecretKeyRingCollection secretKeyRingCollection(String asciiArmored) throws IOException, PGPException {
+        return secretKeyRingCollection(asciiArmored.getBytes(UTF8));
+    }
+
+    /*
+    STATIC METHODS
+     */
+
+    public static PGPPublicKeyRing readPublicKeyRing(InputStream inputStream) throws IOException {
+        return new PGPPublicKeyRing(
+                PGPUtil.getDecoderStream(inputStream),
+                new BcKeyFingerprintCalculator());
+    }
+
+    public static PGPPublicKeyRingCollection readPublicKeyRingCollection(InputStream inputStream)
+            throws IOException, PGPException {
+        return new PGPPublicKeyRingCollection(
+                PGPUtil.getDecoderStream(inputStream),
+                new BcKeyFingerprintCalculator());
+    }
+
+    public static PGPSecretKeyRing readSecretKeyRing(InputStream inputStream) throws IOException, PGPException {
+        return new PGPSecretKeyRing(
+                PGPUtil.getDecoderStream(inputStream),
+                new BcKeyFingerprintCalculator());
+    }
+
+    public static PGPSecretKeyRingCollection readSecretKeyRingCollection(InputStream inputStream)
+            throws IOException, PGPException {
+        return new PGPSecretKeyRingCollection(
+                PGPUtil.getDecoderStream(inputStream),
+                new BcKeyFingerprintCalculator());
+    }
+}